Heap-based buffer overflow in Microsoft SQL Server - CVE-2026-77481
Published: September 9, 2026
Vulnerability identifier: #VU148413
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-77481
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary code.
The vulnerability exists due to a heap-based buffer overflow in the SQL Server data-handling API when processing a specially crafted parameter in a CLR (SAFE) stored procedure. A remote user can call the API with a specially crafted parameter to execute arbitrary code.
Exploitation requires the ability to create and execute a CLR (SAFE) stored procedure and does not require user interaction.
Affected software
Microsoft SQL Server
How to mitigate CVE-2026-77481
Install security update from vendor's website.
Microsoft SQL Server - addressed in versions 14.0.2130.4, 14.0.3550.4, 15.0.2190.7, 15.0.4490.9, 16.0.1200.5, 16.0.4275.2, 17.0.1135.8, 17.0.4085.5